”Since Russia’s invasion of Ukraine, the dark fleet of old vessels that lack proper insurance, have opaque ownership, and “flag hop” between different permissive ship registries has grown explosively, to an estimated 1,400 ships. Their presence poses considerable risk to other ships, to the environment, and to countries experiencing maritime accidents caused by the vessels.
In addition to serving the transportation needs of Russia (as well as Iran, North Korea, and Venezuela), the shadow fleet forms quintessential “gray zone” aggression, causing tangible harm that targeted countries can do little to punish. If countries do try to block dark ships from their waters, or escort them away, it could prompt retaliation and escalation by Russia.”
https://www.atlanticcouncil.org/in-depth-research-reports/issue-brief/russias-growing-dark-fleet-risks-for-the-global-maritime-order
